Backlit illuminated signage generally includes a sign face, which typically comprises a transparent front member having a paper or polymeric film attached thereto. As used herein the term “transparent” means that a material or film does not absorb a significant amount of visible radiation and does not reflect a significant amount of visible radiation; rather, visible radiation is transmitted through the material. The paper or polymeric film structure can include a desired image, communication, indicia, or information thereon. In general, backlight or backlit applications are those in which the sign face is illuminated from a side (i.e. back) of the polymeric film structure that is opposite to the side (i.e. front) from which the sign face is intended to be viewed. The sign face may be illuminated also from the front or in some instances from the side or edge.
In backlight applications, the polymeric film structure is typically transparent, semitransparent, or translucent. Typically, the sign face, including the film structure, is held in front of a light source, which illuminates the sign face from behind. While such backlit signs or displays are generally acceptable, they do have certain limitations and/or drawbacks. For example, when the illumination source includes multiple point light sources, such as light emitting diode (LED) arrays, the light from the illumination source may unevenly illuminate the sign face.